- Vincristine sulfate is a widely used antineoplastic agent of the alkaloid class of drugs derived from the periwinkle plant (Vinca rosea Linn.). It has activity against a wide number of malignancies. It is a cell-cycle-specific agent that arrests cell growth in the M-phase (metaphase) by binding specifically with tubulin and disrupting cell division. Its dose limiting toxicity (DLT) is virtually always neurological.